1. What intermolecular forces have we covered so far (there are three)?

2. Briefly describe each.

Day 5 1-7

C. London Dispersion Forces

1. London dispersion forces exist between _________ _________ and are

found in ____ ___________

2. Induced dipoles and instantaneous dipoles arise when the ________

clouds of atoms or molecules are _________ by an outside influence such as a collision.

nonpolar particlesAll substances

electron

distorted

3. Polarizability is the _____ in distorting or “squashing” the electron cloud.

4. The _________ of the dispersion forces depends upon several factors

________ of _________

- more electrons = more polarizable (easier to

distort) stronger dispersion forces

ease

strength

numberelectronsHe vs. Ne

4. The _________ of the dispersion forces depends upon several factors

_____ or ____

- more mass = more polarizable (easier to distort) stronger dispersion forces

strength

mass sizeCH4 vs. C6H14

D. Hydrogen Bonding

1. Hydrogen bonding is the attraction of an atom of _________ from one

molecule to an atom with a high ________________ in another molecule, especially __, __, & __.

hydrogen

electronegativity F O N

2. Hydrogen bonds affect compound characteristics such as _____________

__________________________________________________________________

3. Diagram an example: H2O mixed with NH3 and HF (see also p 390)

boiling point, phase at room temp., shape (DNA), density see C and H p 391

1.

In the table above the boiling points increase with _________________ molecular weight because the London dispersion forces are _________________. 2. Which of the following substances is most likely to exist as a gas at room temperature and normal atmospheric pressure: P4O10, Cl2, AgCl, I2?  

Noble Gas Boiling Point (K)He 4.6Ne 27.3Ar 87.5Kr 120.9Xe 166.1

E. van der Waals Forces is an umbrella term for the intermolecular forces _________________, ____________, and __________________.

F. How do the intermolecular forces compare in strength?

london dispersion

dipole-dipolehydrogen

bonding

london < dip.-dip. < H-bond < ion-dip. < ion-ion (for solids)

Why do compounds with strong intermolecular attractive forces have higher boiling points than compounds with weak intermolecular forces?

Day 6 1-8

page 257 #s 64, 65, 66, 67 …

page 181 = electronegative valuesAmmonia = NH3

1. Read the half sheet on Self-cleaning windows and answer the question at the bottom.

Day 1 1-9

Periods 1 & 3 = Monday 1-14 day 4

Day 6 1-8

E. van der Waals Forces is an umbrella term for the intermolecular forces _________________, ____________, and __________________.

F. How do the intermolecular forces compare in strength?

london dispersion

dipole-dipolehydrogen

bonding

london < dip.-dip. < H-bond < ion-dip. < ion-ion (for solids)

III. Properties of Liquids

A. Viscosity is a liquid’s ____________ to _____.

1. Higher viscosity indicates _____________, ___________, & _______________

resistanceflow

“thickness”slow flowStrong bonds

2. Lower viscosity indicates ____________, __________, & _____________

3. Temperature affects viscosity.

a. How?

b. Why?

“thinness”fast flowweak bonds

- T up, KE up, movement/flow up

- T up, viscosity down,

Chapter 11 Homework # 1 – 10 correct

http://wps.prenhall.com/esm_brown_chemistry_9/2/660/169060.cw/index.html

Day 2 1-10

1. Which liquid should be more viscous at room temperature honey or rubbing alcohol? 2. What if the honey is cooled by 10 degrees and the rubbing alcohol is heated by 10 degrees?   3. What intermolecular forces exist for NH3? Put them in increasing order of strength.

Periods 1 & 3 = Tuesday 1-15 Day 5

Day 2 1-10

B. Surface Tension

1. Surface tension = net ________ force on the particles at a _________ surface

a. “Skin” is visible as molecules are ________ __________.

b. Creates ___________ shape and less _________ ______

inwardliquid’s

packedtogether

surfaceareaspherical

2. Capillary action is a liquid’s rising in a _________ ______ until cohesive and adhesive forces _________.

Examples:

narrow tubebalance

3. Meniscus shape depends on strengths of cohesion versus adhesion.

a. H2O shape indicates stronger ___________ and weaker __________

b. Hg shape indicates stronger __________ and weaker ___________

cohesion adhesion

adhesion

cohesion

cohesion

adhesion

water sticking to water

water sticking to another polar substance

IV. Vapor Pressure

A. Vapor pressure is the pressure just above the _________ of a _______ or ______ as the particles escape into the air.

B. Volatility1. Liquids that are volatile ___________ easily.

surface liquidsolid

evaporate

2. Volatility depends on _________________,

________________________,

vapor pressure

intermolecular forces

Higher vapor pressure = MORE volatile

Weaker intermolecular forces of attraction = MORE volatile

2. Volatility depends on ______________, and ______________.

C. Boiling

1. ______ ___________ = __________ __________

size / weight temperature

vapor pressure externalpressure

C. Boiling

2. What obstacles must a water molecule overcome in order to boil?

Intermolecular forces, especially H bonds (love of neighbors & family)

Surface tension (surface sentinels who goes there?)

Pressure from outside (kept down by “the Man”)

1. How could we get water to boil withOUT changing temperature?

2. Which is more volatile water or methane? Explain reasoning!

methane =

1-11 Day 3

C H H

H

H

Page 257 #s 70 and 75 (all parts)

page 257 #s 64, 65, 66, 67 …

page 181 = electronegative valuesAmmonia = NH3

Due Friday 1-11

Critical temperature – the highest temp. at which a substance can exist as a liquid (greater intermolecular attractive forces = higher critical temp. substance would rather be liquid)

critical pressure – pressure necessary to achieve liquid at critical temp.

Triple point – temp. at which solid, liquid, and gas phases coexist in equilibrium

* During a phase change, temperature does NOT change (slope = 0)

AS WE HEAT A SOLID!

Chapter 11 Homework # 2 – 11 correct

http://wps.prenhall.com/esm_brown_chemistry_9/2/660/169060.cw/index.html

1-11 Day 3